The present invention relates to tailgate or end-gate devices implemented on transport-type vehicles used in material handling industries and businesses, such as hauling, shipping, construction, excavation, refuse, storage, maintenance, and light industrial and commercial applications. More particularly, this invention relates to pivotable xe2x80x9cdump-stylexe2x80x9d tailgates, and split tailgates that are dually rotatable.
Generally, transport vehicles used for material handling are equipped with tailgates designed to fulfill one function; often these tailgates take one of two forms. The first type is a dump-style tailgate that pivots about a horizontal axis at the top of the tailgate while latching at the bottom during transit. The second design has a side hinge and rotates about a vertical axis in barn door fashion; this type of tailgate has been created using both a single door or split door construction.
Dump-style tailgates (those that pivot about a horizontal axis at the top) are usually designed for vehicle beds that can be raised in the front causing the material contained to shift to the rear of the bed where it is dumped through the tailgate. Although this tailgate design provides an expedient way to unload material with relatively little manpower, the dump-style tailgate does not provide easy access to the vehicle bed. As a result, situations requiring material to be loaded and unloaded by hand or calling for any other accessibility to the vehicle bed would be complicated by a dump-style tailgate design.
In such cases, a side-hinge tailgate (one that rotates about a vertical axis on the side of the tailgate) provides more accessibility to the vehicle bed. A one-piece door construction is hinged on a vertical axis at an end of the tailgate allowing a single tailgate door to open to one side. Though the tailgate door permits ready access to the vehicle""s bed, it can be problematic where the vehicle faces space constraints. For example, a vehicle loading or unloading in a confined space, such as a tight alleyway or between trees, may not have adequate room for the tailgate door to fully open where its width is equal to that of the vehicle bed itself. Thus, in tight spaces such a tailgate would be useless. An alternate side-hinge tailgate has been developed to combat space constraints in which the door is split and hinged on both vertical ends of the tailgate so that each door panel dually rotates about a vertical axis. By splitting the tailgate door, only a portion of the entire bed width is needed to open the door, thereby minimizing the inability to load and unload in narrow spaces.
In each of these constructions, however, the user is still limited to either the dump-style or side-hinge door-style tailgate and the limitations of each design""s use. Very few tailgates have been designed which permit the user to alternate between use of the same tailgate as either dump or side-hinge style. However, those tailgates that have been designed to operate as both dump and side-hinge style pose several drawbacks. For example, these dual-purpose tailgates ordinarily employ the one-piece side-hinge style door, creating difficulties in confined spaces as mentioned above. Additionally, the operator""s safety is compromised where the operator must disengage the door latch to use the dump-style gate at the rear of the vehicle. Present split-door style tailgates often position the door latch in the center of the tailgate forcing the operator to stand directly in front of the vehicle bed. If material shifts during transport, the operator could suffer serious injuries by opening the centrally located door latch because he will be standing directly in front of the load when it falls from the vehicle bed.
Bontrager has developed one type of dually operable tailgate disclosed in U.S. Pat. No. 6,015,191. The Bontrager invention uses a type of dump-style tailgate, but also permits the operator to use the tailgate as a side-hinge gate. The side-hinge gate on the Bontrager invention can be built as either a one-piece or split tailgate; however, the split gate has only one centrally located door latch which appears to require the operator to manually open the latch while standing directly behind the tailgate doors. If materials in the vehicle bed shifted during transport, the operator""s safety could be jeopardized if material fell from the vehicle bed when she opened the central door latch. Additionally, the Bontrager apparatus does not indicate any specialized construction to insure the split door configuration retains its rigidity and alignment while the door is used as a dump-style tailgate. Again, such rigidity and alignment is important for safety reasons. If the tailgate fails to maintain its rigid structure and alignment, it could collapse during transport or while unloading material, resulting not only in loss of the load, but potentially causing personal injury to operators and bystanders.
Accordingly, several objects and advantages of the present Patent Application of Bucks Fabricating, a division of Deist Industries, Inc. for xe2x80x9cTailgate Apparatus Operable as Either a Split Rotatable or Pivotable Gatexe2x80x9d are:
1. To provide a tailgate apparatus for transport-type vehicles useable as either a dump-style (hinged along the top of the tailgate and pivotable on a horizontal axis), or as a split side-hinge tailgate (hinged at each side of the tailgate and dually rotatable along a vertical axis).
2. To provide a more reliable dual purpose tailgate by aligning the side-hinge doors more tightly to increase the rigidity of the structure, thus preventing buckling of the doors.
3. To provide a more convenient tailgate apparatus for operations requiring dump-style applications while also needing ready access to the vehicle bed.
4. To provide a tailgate apparatus designed for use in spaces where a split side-hinge door construction requires less space to access the vehicle bed.
5. To provide a dual purpose tailgate that affords greater safety protections to the operator and to any bystanders where:
(a) The dump gate latch is released at the front of the vehicle bed preventing material from spilling onto the operator.
(b) The split side-hinge door latches are disengaged by a release handle located on the side of the door opening preventing material from spilling onto the operator.
(c) The split door alignment is designed for greater rigidity to prevent buckling of the doors during transit or operation.
6. To provide a dual-purpose tailgate that is simpler to operate where it uses a forward release latch system and fewer pins are needed in interchanging between door uses.
In accordance with the present invention a two-piece tailgate apparatus operable as either a rotatable or pivotable gate comprises both a rotatable and pivotable mount enabling the tailgate to rotate about either horizontal or vertical axes so that the tailgate door panel(s) open on one or both ends, or alternatively along the top. The tailgate apparatus encompasses safety features allowing the operator to open the door panel(s) without being directly in front of the cargo area. Additionally, the door panel(s) are designed to use angular locking and positioning mechanisms to create a more rigid tailgate structure that prevents buckling and collapsing of the door panel(s) during operation.